This program has a common interest in responses of large and small vessels and of their endothelial and smooth muscle cells to injury. Fundamental questions are being asked related to basic pathologic processes that may be involved in atherosclerosis. Mechanisms that permit or stimulate cell replication, cell migration and cellular interactions are being investigated. The potential role of mechanical and toxic injuries, of the metabolic products of xenobiotics and the mechanism whereby herpesviruses may produce proliferative lesions in animals and human beings are being investigated. The program includes studies of the nature of changes in ploidy of smooth muscle with age and hypertension studies. Mechanisms of interaction of leukocytes, endothelial cells, of the HDL apoprotein and ApoSAA are also being investigated. A wide range of methods are being used including cell culture, histoimmunocytochemistry, flow cytophotometry, scanning electron microscopy and molecular probes for viral and amyloid protein genes in cells.